Mystery rapper Mommy Son mentioned Mad Clown.

On January 19, Mommy Son guested on KBS2's 'Yoo Hee Yeol's Sketchbook.' The rapper commented, "I'm honored to be on the stage of 'Sketchbook,' where musicians dream of standing on."

When the MC asked about Mad Clown, Mommy Son said, "His waiting room was right next door but I wasn't able to see him." The MC continued to ask about his identity. Mommy Son remained silent, making his identity an ongoing mystery.